Teachers matter. A lot. Studies show that students with the best teachers learn three times as much as students with the worst teachers.
Researchers say the achievement gap between poor children and their higher-income peers could disappear if poor kids got better teachers.

Politicians and education reformers are calling for big changes in how teachers are trained and evaluated – and in the way teachers are hired and fired too.

Students who get the best teachers learn more. Students who get the worst teachers fall behind.

Researchers don't know exactly what it is that makes effective teachers so good at what they do.